Efficacy and safety of carnitine supplementation on NAFLD: a systematic review and meta-analysis

Abstract

Abstract Background & Objective: The efficacy and safety of L-carnitine supplementation on Non-alcoholic fatty liver disease (NAFLD) is unclear. This systematic review and meta-analysis aimed to assess the efficacy and safety of L-carnitine supplementation on NAFLD. Methods: We searched in four databases (PubMed, Embase, Cochrane Library, and Web of Science) from inception to 1 November 2022 for potentially relevant records without language restrictions. We collected information on first author, publication year, country, setting, study design, population characteristics, duration of follow-up, outcome variables of interest, and sources of funding. We using a modified Cochrane risk of bias tool assessed the risk of bias, and using GRADE assessed the certainly of evidence, and using the Credibility of Effect Modification Analyses (ICEMAN) tool assessed the credibility of any apparent subgroup effect. Results:This systematic review and meta-analysis included eight eligible randomised controlled trials (RCTs). Low certainty evidence show that L-carnitine supplementation significantly changes (reduced) in the AST levels and ALT levels (MD: -26.38, 95%CI: -45.46 to -7.30). Moderate certainty evidence show that L-carnitine supplementation significantly changes in the HDL-cholesterol levels (MD: 1.14, 95%CI: 0.21 to 2.07) and the Triglyceride levels (MD: -6.92, 95%CI: -13.82 to -0.03). Moderate credibility of ICEMAN result show that L-carnitine supplementation no difference on changes of AST and ALT levels in younger (MD: 0.5, 95%CI: -0.70 to 1.70), but have significantly changes (reduced) in the adults (MD: -20.3, 95%CI: -28.62 to -12.28). Conclusion: L-carnitine supplementation may improve liver function and regulates triglyceride metabolism in patients with NAFLD, and with no significant adverse effects.